This invention relates to methods and systems for optimizing operation of vehicle control systems based on the critical dynamics of the particular vehicle,
Automotive vehicles are built by the manufacturer according to the manufacturer's specification. That is, the manufacturer controls the specifications of each manufactured vehicle thereby having knowledge of each vehicle's critical dynamics. Thus, the manufacturer can design the various vehicle control systems accordingly to optimize their performance. Examples of vehicle control systems include automatic gearshift systems, vibration control systems, antilock brake systems, traction control systems, and vehicle stability systems.
Heavy vehicles, such as trucks, on the other hand, are typically custom-built according o the buyer's specification. Several options exist for many of the components including, but not limited to, the engine, clutch, transmission, driveline, drive axles, brakes, and suspension systems. The specification of any resultant commercial truck, therefore, is not known in advance of the manufacture of the vehicle. Consequently, the effectiveness of each of the various vehicle control systems is often compromised in commercial vehicles due to the poor or insufficient estimation of the critical dynamic and vibratory characteristics of the system being controlled. These characteristics, such as natural frequencies and damping ratios, define the system's transient and steady state response characteristics, which in turn define optimum values for active or passive control parameters such as gains, decay rates, and filter parameters.
Often, the lack of specific knowledge can result in less than optimum control of a vehicle in operation. As an example, a torque control typically is limited to avoid operation at the natural powertrain torsional frequency. Given the potential range across possible vehicles, designers often compromise operation to ensure that the torque control will not result in the vehicle operating at its natural frequency. That is, a margin of error must be factored into the control to accommodate all possible vehicle combinations and the resultant range in natural frequencies.
Thus, there exists a need to optimize effectiveness of vehicle control systems for the wide range of powertrain and suspension dynamic and vibratory characteristics of highly configurable vehicles.